New gamemode and UI update.

This devlog I added a new gamemode which focuses in a new major mechanic: powers!

These can spawn randomly on the map and each grants a new ability:

• The Armor power gives you a very strong armor that makes you immune to any attack, but that doesn't let you shoot.
• The Add Cannon power adds a new cannon in the back of the player, allowing you to explode double the tanks.
• The Zoom Out power zooms the camera out, giving you more insight on the location of your next victims.
• The Double Points power gives you double the points for every tank destroyed(obviously).

Try to experiment with these, but remember that some powers may have incompatibilities with others.

The other major change was a very much needed update to the main menu, to match it with the original. Now, only the main menu was changed, but the pause screen also needs some improvement. Maybe in the next update ;)